Answer:
In Java:
import java.util.*;
public class Main{
public static int countgrades(char[]letterGrades,char Grade, int lent){
int count = 0;
for(int i =0;i<lent;i++){
if(letterGrades[i]==Grade){
count++; } }
return count;
}
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int lent;
System.out.print("Length: ");
lent = input.nextInt();
while(lent >30 || lent<1){
System.out.print("Invalid input\nLength: ");
lent = input.nextInt(); }
char[] letterGrades = new char[lent];
for(int i =0; i<lent;i++){
letterGrades[i] = input.next().charAt(0);
}
char[] letters = {'A','B','C','D','F'};
for(char i:letters){
System.out.println(i+": "+countgrades(letterGrades,i, lent));
}
}
}
Explanation:
See attachment where I I used comment to explain each lin e